undo Dockerfile changes

.github/workflows/build-images.yml

@@ -47,19 +47,7 @@ jobs:
 
       - name: Build Docker Images
         run: |
-          cargo build --locked --release --features default
-          docker build -t kilt-node .
-
-
-      - name: Push Image - Commit SHA
-        if: github.ref_type == 'branch'
-        run: |
-          ./.maintain/push-image.sh build "${{ env.CI_COMMIT_SHORT_SHA }}"
-
-      - name: Push Image - Latest Branch
-        if: github.ref_type == 'branch'
-        run: |
-          ./.maintain/push-image.sh build "latest-${{ env.CI_COMMIT_BRANCH }}"
+          ./.maintain/build-image.sh build
 
       - name: Push Image - Tag
         if: startsWith(github.ref, 'refs/tags/')

Dockerfile

@@ -1,9 +1,25 @@
+# this container builds the kilt-parachain binary from source files and the runtime library
+# pinned the version to avoid build cache invalidation
+
+FROM paritytech/ci-unified:bullseye-1.70.0 as builder
+
+WORKDIR /build
+
+ARG FEATURES=default
+
+COPY Cargo.toml Cargo.lock ./
+COPY ./src ./src
+
+RUN cargo build --locked --release --features $FEATURES
+
+# ===== SECOND STAGE ======
+
 FROM docker.io/library/ubuntu:20.04
 LABEL description="This is the 2nd stage: a very small image where we copy the kilt-parachain binary."
 
 ARG NODE_TYPE=kilt-parachain
 
-COPY ./target/release/$NODE_TYPE /usr/local/bin/node-executable
+COPY --from=builder /build/target/release/$NODE_TYPE /usr/local/bin/node-executable
 
 RUN useradd -m -u 1000 -U -s /bin/sh -d /node node && \
 	mkdir -p /node/.local/share/node && \